Laminated body and packaging bag

Abstract

A laminate having a structure in which at least a paper substrate, an anchor coat layer, an aluminum vapor deposition layer, and a top coat layer are laminated in this order, the laminate being characterized in that the half-value width of the peak of the (111) crystal plane of aluminum as determined by X-ray diffraction measurement of the aluminum vapor deposition layer is 1.6 DEG or more.

Description

Technical Field

[0001] The present disclosure relates to a laminate and a packaging bag. Background Art

[0002] In many fields such as food, beverages, pharmaceuticals, and chemicals, packaging materials are used according to their respective contents. Packaging materials are required to have anti-permeability (gas barrier properties) to water vapor, etc., which may cause the deterioration of the contents. In addition, packaging materials are required to have oil resistance to prevent the oil contained in the contents from leaking out, depending on the contents.

[0003] In recent years, due to the increase in environmental awareness caused by the problem of marine plastic waste, the trend of plastic removal has been rising. From the perspective of reducing the amount of plastic materials used, the use of paper as a substitute for plastic materials is being studied in various fields. For example, the following Patent Document 1 discloses a laminated body in which a barrier layer is laminated on paper.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-69783 Summary of the invention

[0007] Problems to be solved by the invention

[0008] Paper has the characteristic of being easy to process because it has crease retention (also called dead fold retention). However, according to the research of the present inventors, it was found that in the case of packaging bags with more acute creases (pillow packaging, three-side sealed packaging and accordion packaging), cracks are generated in the barrier layer and the oil resistance is reduced, which still has room for improvement.

[0009] In addition, from the viewpoint of the Act for Promotion of Effective Utilization of Resources, it is required to reduce the amount of plastic material used in laminates.

[0010] Therefore, an object of the present disclosure is to provide a laminate using paper which has not only initial oil resistance but also sufficient oil resistance even after being folded, and a packaging bag including the laminate.

[0011] Means for solving problems

[0012] In order to solve the above-mentioned problems, the present disclosure provides the following laminated body and packaging bag.

[0013] [1] A laminate having a structure in which at least a paper substrate, an anchor coating, an aluminum vapor-deposited layer and a top coating are sequentially laminated, wherein the half-value width of the peak of the aluminum (111) crystal plane obtained by X-ray diffraction measurement of the aluminum vapor-deposited layer is greater than 1.6°.

[0014] [2] The laminate according to [1] above, wherein the anchor coating layer comprises a polyolefin or polyvinyl alcohol-based resin having a polar group.

[0015] [3] The laminate according to [1] or [2] above, wherein the top coat layer contains a polyolefin having a polar group.

[0016] [4] The laminate according to any one of [1] to [3] above, wherein the hardness of the anchor coating layer measured by nanoindentation in a cross section in the thickness direction of the laminate is 0.3 GPa or less.

[0017] [5] The laminate according to any one of [1] to [4] above, wherein the hardness of the top coating layer measured by nanoindentation in a cross section in the thickness direction of the laminate is 0.3 GPa or less.

[0018] [6] The laminate according to any one of [1] to [5] above, wherein the thickness of the aluminum vapor-deposited layer is 20 nm to 100 nm.

[0019] [7] The laminate according to any one of [1] to [6] above, wherein the half-value width of the peak of the (111) crystal plane of aluminum obtained by X-ray diffraction measurement of the aluminum vapor-deposited layer is greater than or equal to 2.0° and less than or equal to 15.0°.

[0020] [8] The laminate according to [7] above, wherein the aluminum vapor-deposited layer is in contact with a resin layer containing an ionomer or a polyvinyl alcohol-based resin having a saponification degree of 95% or more.

[0021] [9] A packaging bag comprising the laminate according to any one of [1] to [8] above.

[0022]

[10] The packaging bag according to [9] above, which has a folded portion.

[0023] Effects of the Invention

[0024] According to the present disclosure, a laminate using paper can be provided, which has not only initial oil resistance but also sufficient oil resistance even after being bent; and a packaging bag including the laminate. Since the laminate uses paper, it has crease retention, which is a characteristic of paper, and helps to reduce the amount of plastic material used. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic cross-sectional view showing a laminated body according to one embodiment of the present disclosure.

[0026] Figure 2This is a perspective view showing a packaging bag according to one embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate. However, the present disclosure is not limited to the following embodiments.

[0028] <Laminate>

[0029] The laminate of the present embodiment is a laminate as follows: it is a laminate having a structure in which at least a paper substrate, an anchor coating, an aluminum vapor-deposited layer and a top coating are stacked in sequence, wherein the half-value width of the peak of the (111) crystal plane of aluminum obtained by X-ray diffraction measurement of the aluminum vapor-deposited layer is 1.6° or more. Here, the half-value width in the X-ray diffraction of the aluminum vapor-deposited layer represents the degree of lattice strain of the crystal structure of aluminum. When the strain is large, the half-value width becomes larger, and when the strain is small, the half-value width becomes smaller. In addition, the smaller the strain, the denser the crystal structure of aluminum. With respect to the above-mentioned laminate, by making the half-value width of the aluminum vapor-deposited layer above 1.6°, the density of the crystal structure of aluminum can be moderately reduced to a sparse state. As a result, the stress applied to the aluminum vapor-deposited layer when the laminate is bent is dispersed in the entire layer, and cracks in the aluminum vapor-deposited layer can be suppressed when bending, and cracks generated in the aluminum vapor-deposited layer can be reduced. Therefore, according to the above-mentioned laminate, not only the initial oil resistance can be obtained, but also sufficient oil resistance can be obtained even after bending. In addition, according to the above-mentioned laminate, by setting the above-mentioned half-value width of the aluminum vapor-deposited layer to the above-mentioned range, not only the initial water vapor barrier can be obtained, but also sufficient water vapor barrier can be obtained even after bending. Furthermore, according to the above-mentioned laminate, when a material having oxygen barrier properties is used for the anchor coating, by setting the above-mentioned half-value width of the aluminum vapor-deposited layer to the above-mentioned range, not only the initial oxygen barrier can be obtained, but also sufficient oxygen barrier can be obtained even after bending. The laminate of this embodiment is useful as an oil-resistant laminate or a gas barrier laminate.

[0030] In addition, there is room for improvement in the degradation of water vapor barrier properties of conventional gas barrier laminates when stored under high temperature and high humidity. For gas barrier laminates whose water vapor barrier properties have deteriorated due to storage under high temperature and high humidity (under 40°C 90% environment), multiple tiny bright spots are confirmed when observed under a microscope using transmitted light, so it is believed that transmission defects are generated in the aluminum vapor deposition layer, thereby deteriorating the water vapor barrier properties. In contrast, the laminate of the present embodiment has an aluminum vapor deposition layer having a half-value width of the peak of the (111) crystal plane of aluminum obtained by X-ray diffraction measurement of 1.6° or more, which can suppress the generation of transmission defects in the aluminum vapor deposition layer even when stored under high temperature and high humidity, and can suppress the degradation of water vapor barrier properties. The inventors of the present invention speculate as follows on the reasons for obtaining this effect.

[0031] The formation of transmission defects in the aluminum vapor deposition layer is affected by the pitting of aluminum caused by corrosive ions and the stretching stress caused by the dimensional change associated with the absorption and dehumidification of the paper substrate. From the perspective of the crystallinity of the aluminum vapor deposition layer, it can be said that the higher the crystallinity, the better the tolerance to corrosive ions, but with regard to stress tolerance, it is believed that the easier it is to follow the stretching of the amorphous, the better. Here, it is believed that the aluminum vapor deposition layer becomes a structure in which the amorphous part fills the surrounding microcrystals. In addition, the wide expansion of the X-ray diffraction line of aluminum comes from the diameter of the microcrystal and the strain of the crystal. It is believed that the state of the width of the X-ray diffraction line is a state in which the microcrystal and the amorphous part composed of the ideal crystal lattice are clearly distinguished. Therefore, it is speculated that in the case of the width of the X-ray diffraction line, it is easy to cause the ideal crystal lattice or the destruction between the crystal / amorphous caused by the pitting and stretching stress in the amorphous part. On the other hand, it is believed that the state in which the X-ray diffraction line is wide takes a deformed crystal structure, and the separation of the crystal part / amorphous part is a blurred state. Therefore, it is speculated that in the case of the wide X-ray diffraction line, the destruction caused by pitting and stretching stress is suppressed, and it is not easy to produce transmission defects. Based on the above reasons, it is believed that when the half-value width obtained by X-ray diffraction of the aluminum vapor-deposited layer is 1.6° or more, even when the laminate is stored under high temperature and high humidity, it is possible to suppress the generation of transmission defects in the aluminum vapor-deposited layer and suppress the deterioration of water vapor barrier properties. This effect is more significantly exerted when the half-value width is 2.0° or more.

[0032] Figure 1 Schematic cross-sectional view showing a laminated body according to one embodiment. A laminated body 10 according to one embodiment includes a paper substrate 1, an anchor coating layer 2, an aluminum vapor-deposited layer 3, and a top coating layer 4 in this order.

[0033] The thickness of the laminate 10 may be 20 to 100 μm, 30 to 80 μm, or 40 to 60 μm. If the thickness of the laminate 10 is within the above range, the laminate 10 can obtain better water vapor barrier properties and oil resistance not only initially but also after being bent.

[0034] [Paper base material]

[0035] The paper substrate 1 may be paper containing plant-derived pulp as a main component. Specific examples of the paper substrate 1 include high-grade paper, special high-grade paper, coated paper, coated paper, cast-coated paper, molded paper, kraft paper, and glass paper. The weight per unit area of ​​the paper substrate 1 may be 20 to 500 g / m 2 or 30~100g / m 2 .

[0036] The paper substrate 1 may be provided with a coating on at least one side of the paper substrate 1 in contact with the anchor coating 2. In the case where the paper substrate 1 is provided with a coating, the paper substrate 1 may include at least a paper layer and a coating. The coating may also be provided on both surfaces of the paper substrate 1. By providing the coating, in addition to being able to prevent the anchor coating 2 from penetrating into the paper, it is also possible to play a role in filling the unevenness of the paper, and the anchor coating 2 can be manufactured uniformly without defects. In the coating, for example, various copolymers such as styrene-butadiene, styrene-acrylic, and ethylene-vinyl acetate, polyvinyl alcohol resins, cellulose resins, paraffin (WAX), etc. can be used as binder resins, and clay, kaolin, calcium carbonate, talc, mica, etc. can be included as fillers. The coating may be a clay coating containing at least clay as a filler.

[0037] When the paper substrate 1 has a coating layer, the thickness of the coating layer may be 1.5 μm or more and 15 μm or less. The thickness of the coating layer may be 1.8 μm or more, 3 μm or more, 5 μm or more, or 6 μm or more. The thickness of the coating layer may be 12 μm or less, or 10 μm or less. If the thickness of the coating layer is within the above range, the laminate 10 can obtain better water vapor barrier properties and oil resistance not only at the beginning but also after bending.

[0038] The thickness of the paper substrate 1 may be 20 to 100 μm, 30 to 80 μm, or 40 to 60 μm. If the thickness of the paper substrate 1 is within the above range, the laminate 10 can obtain better water vapor barrier properties and oil resistance not only initially but also after being bent.

[0039] The thickness of the coating layer may be 3 to 25%, or 5 to 20%, of the thickness of the paper substrate 1. If the ratio is within the above range, the laminate 10 can obtain better water vapor barrier properties and oil resistance not only initially but also after being bent.

[0040] The weight of the paper is preferably 50% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more, based on the entire laminate. If the weight of the paper is 50% by mass or more based on the entire laminate, the amount of plastic material used can be fully reduced, and it can be said that the entire laminate is made of paper and has excellent recyclability.

[0041] [Anchor coating]

[0042] The anchor coating layer 2 is provided on the surface of the paper substrate 1 to improve the adhesion between the paper substrate 1 and the aluminum vapor-deposited layer 3 described later and to improve the gas barrier property and oil resistance of the laminate. The anchor coating layer 2 may contain a polyolefin or polyvinyl alcohol-based resin having a polar group.

[0043] In the case where the anchor coating 2 includes a polyolefin having a polar group, the anchor coating 2 has excellent flexibility, can suppress the cracking of the aluminum vapor-deposited layer 3 described later after bending (after folding), and can improve the adhesion between the anchor coating 2 and the aluminum vapor-deposited layer 3. Furthermore, by including a polyolefin having a polar group, a dense film can be formed by utilizing the crystallinity of the polyolefin, and water vapor barrier properties and oil resistance are exhibited. Water vapor barrier properties and oil resistance are exhibited by the crystallinity of the polyolefin, and the polar group exhibits close adhesion with the aluminum vapor-deposited layer 3.

[0044] The polyolefin having a polar group may have at least one selected from the group consisting of a carboxyl group, a salt of a carboxyl group, a carboxylic acid anhydride group, and a carboxylic acid ester.

[0045] As the polyolefin having a polar group, those obtained by copolymerizing ethylene and propylene with unsaturated carboxylic acids (unsaturated compounds having a carboxyl group such as acrylic acid, methacrylic acid, and maleic anhydride), unsaturated carboxylic acid esters, and salts obtained by neutralizing carboxylic acids with basic compounds can be used. In addition, those obtained by copolymerizing with vinyl acetate, epoxy compounds, chlorine compounds, carbamate compounds, polyamide compounds, etc. can also be used.

[0046] Specific examples of the polyolefin having a polar group include copolymers of acrylic acid ester and maleic anhydride, ethylene-vinyl acetate copolymers, and ethylene-glycidyl methacrylate copolymers.

[0047] On the other hand, when the anchor coating layer 2 includes a polyvinyl alcohol-based resin, the polyvinyl alcohol-based resin has a polar group (hydroxyl group), which is easy to combine with a metal such as aluminum in the aluminum vapor-deposited layer 3, so that the adhesion between the aluminum vapor-deposited layer 3 and the anchor coating layer 2 can be easily improved. In addition, such an anchor coating layer 2 has excellent flexibility and can suppress the rupture of the aluminum vapor-deposited layer 3 after bending (after folding). In addition, by including a polyvinyl alcohol-based resin in the anchor coating layer 2, the oxygen barrier property of the laminate can be improved.

[0048] The polyvinyl alcohol resin is a resin containing vinyl alcohol as a structural unit. Examples of the polyvinyl alcohol resin include completely saponified polyvinyl alcohol resins, partially saponified polyvinyl alcohol resins, modified polyvinyl alcohol resins, and ethylene-vinyl alcohol copolymer resins. From the perspective of oxygen barrier properties, the higher the saponification degree of the polyvinyl alcohol resin, the more preferred it is, and it may be 95% or more, or even 98% or more.

[0049] The anchor coating layer 2 may include both a polyolefin having a polar group and a polyvinyl alcohol-based resin.

[0050] The anchor coating layer 2 may contain other components in addition to the polyolefin having a polar group and the polyvinyl alcohol-based resin. Examples of other components include polyolefins other than the polyolefin having a polar group, silane coupling agents, organic titanates, polyacrylic acids, polyesters, polyurethanes, polycarbonates, polyureas, polyamides, polyimides, melamine, and phenols.

[0051] The content of the polyolefin or polyvinyl alcohol-based resin having a polar group in the anchor coating layer 2 may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass.

[0052] The thickness of the anchor coating layer 2 can be, for example, 0.5 μm or more, 1 μm or more, 2 μm or more, 20 μm or less, 10 μm or less, or 5 μm or less. If the thickness of the anchor coating layer 2 is 0.5 μm or more, the unevenness of the paper substrate can be effectively filled, and the aluminum vapor-deposited layer described later can be uniformly laminated. In addition, if the thickness of the anchor coating layer 2 is 20 μm or less, the aluminum vapor-deposited layer can be uniformly laminated while suppressing the cost.

[0053] The anchor coating 2 may have a hardness of 0.3 GPa or less as measured by nanoindentation in a cross section in the thickness direction of the laminate 10. Such an anchor coating 2 has excellent flexibility, can suppress the cracking of the aluminum vapor-deposited layer 3 described later after bending (after folding), and can improve the adhesion between the anchor coating 2 and the aluminum vapor-deposited layer 3.

[0054] As the solvent contained in the coating liquid of the anchor coating 2, for example, water, methanol, ethanol, isopropanol, n-propanol, n-butanol, n-pentanol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, toluene, hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, butyl acetate can be cited. These solvents can be used alone or in combination of two or more. Among them, methanol, ethanol, isopropanol, toluene, ethyl acetate, methyl ethyl ketone, and water are preferred from the viewpoint of characteristics. In addition, methanol, ethanol, isopropanol, and water are preferred from the viewpoint of environment.

[0055] The anchor coating layer 2 can be provided by applying a coating liquid containing the above-mentioned polyolefin or polyvinyl alcohol-based resin having a polar group and a solvent on a paper substrate and drying the coating liquid.

[0056] [Aluminum vapor deposition layer]

[0057] The aluminum vapor-deposited layer 3 is a layer on which aluminum or an aluminum compound is vapor-deposited. The aluminum vapor-deposited layer may be a layer obtained by vapor-depositing aluminum or a layer containing aluminum oxide (AlO x ), silicon oxide (SiOx ) and other layers.

[0058] The thickness of the aluminum vapor-deposited layer 3 can be appropriately set according to the intended use, preferably 10 to 300 nm, more preferably 20 to 100 nm, and further preferably 30 to 100 nm. By making the thickness of the aluminum vapor-deposited layer 3 above 10 nm, it is easy to make the continuity of the aluminum vapor-deposited layer 3 sufficient, and by making it below 300 nm, it is possible to fully suppress the occurrence of curling and cracking, and it is easy to achieve sufficient gas barrier performance, oil resistance and flexibility. In addition, by setting the thickness of the aluminum vapor-deposited layer to above 20 nm and below 100 nm, the aluminum vapor-deposited layer is less likely to break, and sufficient water vapor barrier properties and oil resistance can be obtained even after bending. From the viewpoint of further suppressing the deterioration of the water vapor barrier properties of the laminate 10 when stored under high temperature and high humidity, the thickness of the aluminum vapor-deposited layer 3 can be 50 to 300 nm, 60 to 150 nm, or 60 to 100 nm.

[0059] From the viewpoint of water vapor and oxygen barrier performance, oil resistance, and film uniformity, it is preferred to form the aluminum vapor deposition layer 3 by vacuum film forming means. Film forming means include well-known methods such as vacuum evaporation method, sputtering method, chemical vapor deposition method (CVD method), but vacuum evaporation method is preferred due to its fast film forming speed and high productivity. In addition, among the vacuum evaporation methods, the film forming method using electron beam heating is particularly effective because it is easy to control the film forming speed using the irradiation area, electron beam current, etc., and can heat and cool the evaporation material in a short time.

[0060] The aluminum vapor-deposited layer 3 is a layer in which the half-value width of the peak of the (111) crystal plane of aluminum measured by X-ray diffraction is 1.6° or more. The above-mentioned half-value width can also be 1.8° or more, or 2.0° or more, or 2.1° or more. When the half-value width is 1.6° or more, it is possible to suppress the generation of cracks in the aluminum vapor-deposited layer 3 when the laminate 10 is bent, and it is possible to suppress the reduction of gas barrier properties and oil resistance after bending. This effect is more significantly exerted when the above-mentioned half-value width is 2.0° or more. In addition, when the above-mentioned half-value width is 1.6° or more, even when the laminate 10 is stored under high temperature and high humidity (for example, under a 40°C 90% environment), it is possible to suppress the generation of transmission defects in the aluminum vapor-deposited layer 3, and it is possible to suppress the deterioration of the water vapor barrier properties of the laminate 10. This effect is also more significantly exerted when the above-mentioned half-value width is 2.0° or more. From the perspective of the density of the aluminum crystal structure, the upper limit of the half-value width can be, for example, less than 15.0°, or less than 10.0°. If the resin layer in contact with the aluminum vapor-deposited layer contains an ionomer or a polyvinyl alcohol-based resin with a saponification degree of 95% or more, the aluminum vapor-deposited layer is easily corroded. If the crystallinity of the aluminum vapor-deposited layer is low, this problem is likely to occur. If the half-value width is less than 15.0°, even if the resin layer in contact with the aluminum vapor-deposited layer contains an ionomer or a polyvinyl alcohol-based resin with a high saponification degree, it is not easy to cause corrosion of the aluminum vapor-deposited layer. This effect is also more significantly exerted when the half-value width is less than 10.0°. In order to take into account the above-mentioned effects, the above-mentioned half-value width is preferably greater than 1.6° and less than 15.0°, greater than 1.6° and less than 10.0°, greater than 1.6° and less than 7.0°, greater than 1.6° and less than 5.0°, greater than 2.0° and less than 15.0°, greater than 2.0° and less than 10.0°, greater than 2.0° and less than 7.0°, or greater than 2.0° and less than 5.0°.

[0061] The half-value width (2θ) of the peak of the (111) crystal plane of aluminum in the aluminum vapor-deposited layer 3 is measured using an X-ray diffraction device. As an X-ray diffraction device, for example, ATX-G (trade name) manufactured by Rigaku Corporation can be used. The measurement can be performed from the top coat 4 by fixing the laminate as a sample on a glass slide. As the X-ray diffraction of aluminum, the half-value width of the peak at 2θ=38.5° corresponding to the (111) plane (d=2.34) is measured. The measurement conditions are as follows.

[0062] Light source: CuKα rays

[0063] Tube voltage: 50kV

[0064] Tube current: 300mA

[0065] Optical system: parallel beam optical system

[0066] Scanning method: 2θ / θ method

[0067] Measuring range: 30°~50°

[0068] Sampling step: 0.02°

[0069] Scanning speed: 2° / min

[0070] Slit

[0071] S1: 10.0mm×1.0mm

[0072] S2: 10.0mm×0.5mm

[0073] Sollar(res):0.4mm

[0074] The half-value width can be controlled by adjusting the conditions during the film formation of the aluminum vapor deposition layer 3. For example, the half-value width can be controlled by adjusting the pressure in the vapor deposition chamber during the film formation of the aluminum vapor deposition layer 3. Here, if the pressure in the vapor deposition chamber is increased, the half-value width can be increased, and if the pressure in the vapor deposition chamber is reduced, the half-value width can be reduced. From the perspective of easily adjusting the half-value width to above 1.6°, the pressure in the vapor deposition chamber during the film formation of the aluminum vapor deposition layer 3 can be above 0.05Pa, can be above 0.10Pa, and can be above 0.20Pa. The upper limit of the pressure is not particularly limited as long as it is within the range in which the aluminum vapor deposition layer 3 can be formed, for example, it can be below 0.50Pa, and can also be below 0.40Pa.

[0075] [Top coating]

[0076] The top coat layer 4 is provided on the surface of the aluminum vapor-deposited layer 3 so as to be in contact with the aluminum vapor-deposited layer 3. The top coat layer may contain a polyolefin having a polar group.

[0077] The polyolefin having a polar group may have at least one selected from the group consisting of a carboxyl group, a salt of a carboxyl group, a carboxylic acid anhydride group, and a carboxylic acid ester.

[0078] As the polyolefin having a polar group, those obtained by copolymerizing ethylene and propylene with unsaturated carboxylic acids (unsaturated compounds having a carboxyl group such as acrylic acid and methacrylic acid), unsaturated carboxylic acid esters, and salts obtained by neutralizing carboxylic acids with basic compounds can be used. In addition, those obtained by copolymerizing with vinyl acetate, epoxy compounds, chlorine compounds, carbamate compounds, polyamide compounds, etc. can also be used.

[0079] Specific examples of the polyolefin having a polar group include copolymers of acrylic acid ester and maleic anhydride, ethylene-vinyl acetate copolymers, and ethylene-glycidyl methacrylate copolymers.

[0080] By including a polyolefin having a polar group, the top coat 4 has excellent flexibility, can suppress the cracking of the aluminum vapor-deposited layer after bending (after folding), and has excellent adhesion to the aluminum vapor-deposited layer. Furthermore, by including the above-mentioned polyolefin having a polar group, it is possible to form a dense film by utilizing the crystallinity of the polyolefin, and exhibit water vapor barrier properties and oil resistance. In addition, by having a polar group, it exhibits close adhesion to the aluminum vapor-deposited layer. In addition, by including the above-mentioned polyolefin having a polar group, the top coat 4 can also serve as a heat-sealing layer, so a heat-sealing layer may not be provided separately.

[0081] The top coat layer 4 may contain other components in addition to the above-mentioned polyolefin having a polar group. Examples of other components include silane coupling agents, organic titanates, polyacrylic acid, polyester, polyurethane, polycarbonate, polyurea, polyamide, polyolefin emulsion, polyimide, melamine, phenol, and the like.

[0082] The content of the polyolefin having a polar group in the top coat layer 4 may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass.

[0083] The thickness of the topcoat layer 4 can be, for example, 0.05 μm or more, 0.5 μm or more, 1 μm or more, 2 μm or more, 20 μm or less, 10 μm or less, or 5 μm or less. If the thickness of the topcoat layer 4 is 0.05 μm or more, the above-mentioned role as a heat seal layer can be fully exerted. In addition, if the thickness of the topcoat layer 4 is 20 μm or less, the adhesion and barrier properties with the aluminum vapor-deposited layer can be fully exerted while suppressing the cost. In addition, by making the thickness of the topcoat layer 4 2 μm or more and 10 μm or less, the aluminum vapor-deposited layer is less likely to break, and sufficient water vapor barrier properties and oil resistance can be obtained even after bending.

[0084] With regard to the laminate 10, when the top coating 4 contains a polyolefin having a polar group, the thickness of the top coating 4 is set to be greater than 2 μm and less than 10 μm, and the thickness of the aluminum vapor-deposited layer 3 is set to be greater than 20 nm and less than 100 nm, the aluminum vapor-deposited layer 3 is not easy to break, and the effect of being able to obtain sufficient water vapor barrier properties and oil resistance even after bending can be particularly significantly exhibited.

[0085] The hardness of the top coating layer 4 measured by the nanoindentation method in the cross section in the thickness direction of the laminate 10 can be 0.3 GPa or less. Such a top coating layer 4 has excellent flexibility, can suppress the cracking of the aluminum vapor-deposited layer 3 after bending (after folding), and can suppress the reduction of gas barrier properties and oil resistance.

[0086] As the solvent contained in the coating liquid of the top coat 4, for example, water, methanol, ethanol, isopropanol, n-propanol, n-butanol, n-pentanol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, toluene, hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, butyl acetate can be cited. These solvents can be used alone or in combination of two or more. Among them, methanol, ethanol, isopropanol, toluene, ethyl acetate, methyl ethyl ketone, and water are preferred from the viewpoint of characteristics. In addition, methanol, ethanol, isopropanol, and water are preferred from the viewpoint of environment.

[0087] As a method for setting the topcoat layer 4, it can be obtained by applying a coating liquid containing the above-mentioned polyolefin with polar groups and a solvent on the aluminum vapor-deposited layer and drying it. The melting point of the polyolefin with polar groups in the coating liquid is preferably 70 to 160°C, and more preferably 80 to 120°C. If the melting point of the polyolefin with polar groups is low, it has the advantage of being able to reduce the rising temperature during heat sealing. When the melting point of the polyolefin with polar groups is low, the possibility of adhesion in a high temperature environment increases. In addition, from the viewpoint of preventing adhesion, in order to reduce the contact area, the larger the particle size, the better. Although not particularly limited, the particle size can be specifically 1 nm or more, and can also be 0.1 μm or more, and can be 1 μm or less, 0.7 μm or less, and 0.5 μm or less.

[0088] (Method for processing cross-section of measurement specimens based on nanoindentation)

[0089] The measurement based on the nanoindentation method is to measure the anchor coating 2 and the topcoat 4 by implementing the cross section of the stack 10. The stack sample containing the anchor coating 2 and the topcoat 4 is cut with a razor in a long strip or wedge shape and embedded in a resin. As the embedding resin, a photocurable resin (such as D-800 manufactured by Toagosei Co., Ltd.) is used, which is cured by light irradiation after embedding. The cured sample embedding resin is fixed with an AFM sample holding insert, and the cross section of the stack is trimmed and cut with a glass knife at room temperature (25°C). The cross section is cut with a diamond knife at a cutting speed of 1.0 mm / s and a cutting film thickness of 200 nm until it becomes a mirror surface. The sample with the exposed cross section is used for the measurement based on the nanoindentation method in a state fixed with an AFM sample holding insert. As a cross-section cutting device, for example, an ultrathin slicer EMUC7 manufactured by Leica can be used. In addition, the cutting direction is set to a direction parallel to the layer interface.

[0090] (Measurement method based on nanoindentation)

[0091] The hardness and complex elastic modulus of the anchor coating and the topcoat represent the hardness and complex elastic modulus calculated by the nanoindentation method. The nanoindentation method is a method of measuring the mechanical properties of the sample by performing a quasi-static indentation test on the target measurement object. The measuring device can use, for example, Hysitron TI-Premier (trade name) manufactured by Bruker Japan Co., Ltd. The indenter can use a Berkovich-type diamond indenter manufactured by Bruker Japan Co., Ltd. The measurement based on the nanoindentation method first uses a diamond indenter to scan the cross section of the sample, thereby obtaining a shape image of the sample and specifying the measurement position of the desired layer. Then, at room temperature (25°C), after being pressed to a depth of 80nm at an indentation speed of 80nm / second in displacement control mode, it is kept at the maximum depth for 1 second and then unloaded at a speed of 80nm / second. The method for calculating the hardness and complex elastic modulus is to test fused quartz, which becomes a standard sample, in advance and calibrate the relationship between the contact depth and contact projection area between the indenter and the sample. Then, the unloading curve in the region of 60% to 95% of the maximum load during unloading was analyzed by the Oliver-Pharr method, and the hardness and complex elastic modulus were calculated.

[0092] The hardness of the anchor coating 2 and the top coating 4 measured by the nanoindentation method in the cross section in the thickness direction of the laminate 10 can be 0.3 GPa or less. As a result, the deformation stress of the paper substrate caused by the bending of the laminate can be alleviated and directly transmitted to the aluminum vapor-deposited layer, preventing defects from occurring in the aluminum vapor-deposited layer, thereby suppressing the deterioration of the gas barrier properties and oil resistance after bending. From this point of view, the hardness of the anchor coating 2 and the top coating 4 can be 0.25 GPa or less, or 0.2 GPa or less. The lower limit of the hardness is not particularly limited, and from the perspective of obtaining sufficient strength for maintaining gas barrier properties and oil resistance, it can be set to 0.05 MPa or more.

[0093] In order to form a soft anchor coating 2 and a top coating 4 having a hardness of less than 0.3 GPa as measured by a nanoindentation method in a cross section in the thickness direction of the stack 10, it is preferable to use the following resin material to form the anchor coating 2 and the top coating 4, wherein the elongation at break of the dry film of the resin material measured in an atmosphere of 20°C and 65% RH in accordance with JIS K7161 is preferably 150% or more, more preferably 200% or more.

[0094] <Packaging bag>

[0095] Figure 21 is a perspective view showing an accordion bag 20 formed of a laminate 10. A packaging bag is manufactured by sealing the upper opening of the accordion bag 20. The accordion bag 20 has a portion (bend portion B1, B2) where the laminate 10 is bent. The bend portion B1 is a portion where the laminate 10 is valley-folded when viewed from the innermost layer side, and the bend portion B2 is a portion where the laminate 10 is mountain-folded when viewed from the innermost layer side.

[0096] The packaging bag can be formed into a bag shape by folding one laminate in half with the top coating 4 facing each other, bending it appropriately in a desired shape and heat-sealing it, or by overlapping two laminates with the top coating 4 facing each other and then heat-sealing them.

[0097] In the packaging bag of this embodiment, the heat seal strength may be 2 N or more, or 4 N or more. It should be noted that the upper limit of the heat seal strength is not particularly limited, and may be 10 N or less, for example.

[0098] The packaging bag can contain food, medicines, etc. as contents. It is particularly suitable for storing snacks as food. The packaging bag of this embodiment can maintain high gas barrier properties and oil resistance even if it has a shape with a bent portion.

[0099] In addition, in this embodiment, an accordion bag is cited as an example of a packaging bag, but it is also possible to produce, for example, a pillow bag, a three-side sealed bag, or a self-supporting bag using the laminate of this embodiment.

[0100] Example

[0101] Hereinafter, the present disclosure will be described in further detail by way of examples, but the present disclosure is not limited to these examples.

[0102] <Production of Laminated Body>

[0103] (Example 1)

[0104] An aqueous dispersion of a polyolefin containing a salt of a carboxyl group (manufactured by Sumitomo Seika Chemicals, Ltd., trade name: Zycene AC, particle size: less than 0.2 μm, solvent: water / IPA=1 / 1 (mass ratio), solid content concentration: 22.5 mass%) was applied to the surface of the clay coating side of a paper substrate having a clay coating layer with a thickness of 5 μm (thickness including the clay coating layer: 55 μm) using a rod coater and dried in an oven to form an anchor coating layer with a thickness of 3 μm.

[0105] Next, Al was deposited on the anchor coating layer by vacuum deposition to form an Al deposited layer (aluminum deposited layer) with a thickness of 50 nm. The pressure in the deposition chamber during aluminum deposition was adjusted to the value shown in Table 1.

[0106] Next, an aqueous dispersion of a polyolefin containing a salt of a carboxyl group (Mitsui Chemicals, Inc., trade name: CHEMIPEARL S100, particle size: less than 0.1 μm, solvent: water / IPA = 1 / 1 (mass ratio), solid content concentration: 20.0 mass%) was applied on the Al deposited layer using a bar coater, and then dried in an oven to form a top coat layer having a thickness of 3 μm. Thus, a laminate was obtained.

[0107] (Example 2)

[0108] A laminated body was obtained in the same manner as in Example 1 except that the pressure in the vapor deposition chamber was changed to the value shown in Table 1 when forming the Al vapor deposition layer.

[0109] (Example 3)

[0110] A laminate was obtained in the same manner as in Example 1 except that the paper substrate was changed to a paper substrate having a clay coating layer having a thickness of 5 μm (thickness including the clay coating layer: 50 μm).

[0111] (Example 4)

[0112] A laminate was obtained in the same manner as in Example 1 except that the anchor coating layer was formed by the following method. Specifically, an aqueous dispersion of a polyolefin containing a salt of a carboxyl group (manufactured by Mitsui Chemicals, Inc., trade name: CHEMIPEARL S100, particle size: less than 0.1 μm, solvent: water / IPA = 1 / 1 (mass ratio), solid content concentration: 20.0 mass%) was applied to the surface of the clay coating layer side of the paper substrate (thickness including the clay coating layer: 55 μm) by a bar coater, and then dried in an oven to form an anchor coating layer having a thickness of 3 μm.

[0113] (Example 5)

[0114] A laminate was obtained in the same manner as in Example 1 except that the topcoat layer was formed by the following method. That is, an aqueous dispersion of a polyolefin containing a salt of a carboxyl group (manufactured by Mitsui Chemicals, Inc., trade name: CHEMIPEARL S500, particle size: 0.7 μm, solvent: water / IPA = 1 / 1 (mass ratio), solid content concentration: 20.0 mass%) was applied on the Al vapor-deposited layer by a bar coater and dried in an oven to form a topcoat layer having a thickness of 3 μm.

[0115] (Examples 6-7)

[0116] A laminated body was obtained in the same manner as in Example 1 except that the pressure in the vapor deposition chamber during formation of the Al vapor deposition layer was changed to the value shown in Table 1 and the thickness of the Al vapor deposition layer was changed to the value shown in Table 1.

[0117] (Example 8)

[0118] A laminate was obtained in the same manner as in Example 1 except that the anchor coating layer was formed by the following method. That is, a solution prepared by dissolving a polyvinyl alcohol (PVA) resin having a saponification degree of 98% and a polymerization degree of 500 in a solvent of water / IPA=8 / 2 (mass ratio) at a solid content concentration of 10% by mass was applied on the surface of the clay coating layer of a paper substrate (thickness including the clay coating layer: 55 μm) by a bar coater, and then dried in an oven to form an anchor coating layer having a thickness of 3 μm.

[0119] (Example 9)

[0120] A laminated body was obtained in the same manner as in Example 8 except that the pressure in the vapor deposition chamber was changed to the value shown in Table 2 when forming the Al vapor deposition layer.

[0121] (Comparative Examples 1-2)

[0122] Except having changed the pressure in the vapor deposition chamber into the value shown in Table 2 when forming the Al vapor deposition layer, it carried out similarly to Example 1, and obtained the laminated body.

[0123] (Comparative Example 3)

[0124] A laminated body was obtained in the same manner as in Example 8 except that the pressure in the vapor deposition chamber was changed to the value shown in Table 2 when forming the Al vapor deposition layer.

[0125] <Preparation of paper substrate>

[0126] As paper substrates, the following clay-coated papers 1 to 3 and uncoated paper 4 were prepared.

[0127] Clay-coated paper 1: Dimensional change rate when changing from temperature 40°C and relative humidity 20% RH to temperature 40°C and relative humidity 90% RH: CD = 0.75%, MD = 0.13%, unit area weight: 60 g / m 2

[0128] Clay-coated paper 2: Dimensional change rate when changing from temperature 40°C and relative humidity 20% RH to temperature 40°C and relative humidity 90% RH: CD = 0.55%, MD = 0.07%, basis weight: 60 g / m 2

[0129] Clay-coated paper 3: Dimensional change rate when changing from temperature 40°C and relative humidity 20% RH to temperature 40°C and relative humidity 90% RH: CD = 0.35%, MD = 0.15%, unit weight: 60 g / m 2

[0130] Uncoated paper 4: Dimensional change rate when changing from temperature 40°C and relative humidity 20% RH to temperature 40°C and relative humidity 90% RH: CD = 1.34%, MD = 0.03%, basis weight: 62 g / m 2

[0131] <Production of Laminated Body>

[0132] (Example 10)

[0133] As a paper substrate, clay-coated paper 1 was prepared. On the clay-coated surface of the paper substrate, an aqueous dispersion of a polyolefin containing a salt of a carboxyl group (manufactured by Sumitomo Seika Chemicals, Ltd., trade name: Zycoene AC, particle size: less than 0.2 μm, solvent: water / IPA=1 / 1 (mass ratio), solid content concentration: 22.5 mass%) was applied using a gravure coater and dried in an oven to form an anchor coating layer having a thickness of 3 μm.

[0134] Next, an Al vapor deposition layer was formed on the anchor coating layer using a roll-to-roll induction heating vacuum vapor deposition apparatus. The pressure in the vapor deposition chamber and the thickness of the Al vapor deposition layer during Al vapor deposition were adjusted to the values ​​shown in Table 3.

[0135] Next, an aqueous dispersion of a polyolefin containing a salt of a carboxyl group (Mitsui Chemicals, Inc., trade name: CHEMIPEARL S100, particle size: less than 0.1 μm, solvent: water / IPA = 1 / 1 (mass ratio), solid content concentration: 20.0 mass%) was applied on the Al vapor-deposited layer using a gravure coater, and then dried in an oven to form a top coat layer having a thickness of 3 μm. Thus, a laminate was obtained.

[0136] (Example 11)

[0137] A laminate was obtained in the same manner as in Example 10 except that the paper substrate was changed to clay-coated paper 2, and the pressure in the vapor deposition chamber and the thickness of the Al vapor deposition layer during formation of the Al vapor deposition layer were changed to the values ​​shown in Table 3.

[0138] (Example 12)

[0139] A laminate was obtained in the same manner as in Example 10 except that the Al deposited layer was formed by the following method. That is, the Al deposited layer was formed on the anchor coating layer using a roll-to-roll EB heating vacuum deposition apparatus. The pressure in the deposition chamber during Al deposition and the thickness of the Al deposited layer were adjusted to the values ​​shown in Table 3.

[0140] (Example 13)

[0141] A laminate was obtained in the same manner as in Example 12 except that the paper substrate was changed to clay-coated paper 2.

[0142] (Example 14)

[0143] A laminate was obtained in the same manner as in Example 12 except that the paper substrate was changed to clay-coated paper 3.

[0144] (Example 15)

[0145] As a paper substrate, clay-coated paper 2 was prepared. On the surface of the paper substrate on the clay coating side, a solution prepared by dissolving polyvinyl alcohol (manufactured by KURARAY CO., LTD., trade name: POVAL5-98) having a saponification degree of 98% and a polymerization degree of 500 at a solid content concentration of 10% by mass in a solvent of water / IPA=8 / 2 (mass ratio) was applied using a gravure coater, and dried in an oven to form an anchor coating layer having a thickness of 4 μm.

[0146] Next, an Al vapor deposition layer was formed on the anchor coating layer using a roll-to-roll EB heating vacuum vapor deposition apparatus. The pressure in the vapor deposition chamber and the thickness of the Al vapor deposition layer during Al vapor deposition were adjusted to the values ​​shown in Table 3.

[0147] Next, an aqueous dispersion of a polyolefin containing a salt of a carboxyl group (Mitsui Chemicals, Inc., trade name: CHEMIPEARL S500, particle size: 0.7 μm, solvent: water / IPA = 1 / 1 (mass ratio), solid content concentration: 20.0 mass%) was applied on the Al vapor-deposited layer using a gravure coater, and then dried in an oven to form a top coat layer having a thickness of 3 μm. Thus, a laminate was obtained.

[0148] (Example 16)

[0149] A laminate was obtained in the same manner as in Example 15 except that the paper substrate was changed to clay-coated paper 1, and the pressure in the vapor deposition chamber and the thickness of the Al vapor deposition layer during formation of the Al vapor deposition layer were changed to the values ​​shown in Table 3.

[0150] (Example 17)

[0151] As a paper substrate, uncoated paper 4 was prepared. On one surface of the paper substrate, a solution prepared by dissolving polyvinyl alcohol (manufactured by KURARAY CO., LTD., trade name: POVAL5-98) having a saponification degree of 98% and a polymerization degree of 500 at a solid content concentration of 10% by mass in a solvent of water / IPA=8 / 2 (mass ratio) was applied using a gravure coater, and dried in an oven to form an anchor coating layer having a thickness of 3 μm.

[0152] Next, an Al vapor deposition layer was formed on the anchor coating layer using a roll-to-roll EB heating vacuum vapor deposition apparatus. The pressure in the vapor deposition chamber and the thickness of the Al vapor deposition layer during Al vapor deposition were adjusted to the values ​​shown in Table 4.

[0153] Next, an aqueous dispersion of ethylene-acrylic acid copolymer resin (manufactured by MICHELMAN, trade name: MC9100, solid content concentration: 20% by mass) was applied onto the Al vapor deposition layer using a gravure coater, and dried using an oven to form a topcoat layer with a thickness of 3 μm. Thus, a laminate was obtained.

[0154] (Comparative Examples 4 to 6)

[0155] A laminate was obtained in the same manner as in Example 10, except that the pressure in the vapor deposition chamber during the formation of the Al vapor deposition layer and the thickness of the Al vapor deposition layer were changed to the values shown in Table 4.

[0156] (Comparative Example 7)

[0157] A laminate was obtained in the same manner as in Example 12, except that the pressure in the vapor deposition chamber during the formation of the Al vapor deposition layer and the thickness of the Al vapor deposition layer were changed to the values shown in Table 4.

[0158] (Comparative Example 8)

[0159] A laminate was obtained in the same manner as in Example 15, except that the pressure in the vapor deposition chamber during the formation of the Al vapor deposition layer and the thickness of the Al vapor deposition layer were changed to the values shown in Table 4.

[0160] <Measurement of the film thickness of the Al vapor deposition layer>

[0161] The laminate was embedded with a UV-curing resin, and the cross-section was cut using a cryostat to prepare a cross-section observation specimen. The cross-section of the specimen was observed with an electron microscope at a magnification of 50,000 times to obtain a SEM image. The thickness of the Al vapor deposition layer was measured from the obtained SEM image. The results are shown in Tables 1 to 4.

[0162] <X-ray diffraction measurement>

[0163] The half-value width of the peak of the (111) crystal plane of aluminum in the Al vapor-deposited layer was measured in the following order. The half-value width was measured using an X-ray diffraction device manufactured by Rigaku Corporation (trade name: ATX-G). The light source used was CuKα rays, the tube voltage was set to 50 kV, the tube current was set to 300 mA, the optical system was set to a parallel beam optical system, the scanning method was set to the 2θ / θ method, the measurement range was set to 30° to 50°, and the scanning speed was set to 2° / min. In addition, the sampling step was 0.02°, the slits were S1: 10.0 mm×1.0 mm, S2: 10.0 mm×0.5 mm, and Solar (res): 0.4 mm. The laminate obtained in the examples and comparative examples was used as a sample, and its paper substrate side was attached to a slide glass with double-sided tape, and X-ray diffraction measurement was performed. As the X-ray diffraction of aluminum, the half value width of the peak at 2θ=38.5° corresponding to the (111) plane (d=2.34) was measured. The results are shown in Tables 1 to 4.

[0164] <Specimen Cross-Section Processing Method>

[0165] The following order is used to prepare the samples for measuring the hardness and complex elastic modulus of the anchor coating and the topcoat of the cross section of the laminate obtained in the embodiment and the comparative example. First, the laminate is cut into a rectangular or wedge-shaped sample containing the anchor coating and the topcoat with a razor, and the obtained sample is embedded in a resin. As the embedding resin, D-800 photocurable resin manufactured by Toagosei Co., Ltd. is used, and it is cured by light irradiation after embedding. The cured sample embedding resin is fixed with an AFM sample holding insert, trimmed and the cross section of the film is cut with a glass knife at room temperature (25°C), and the cross section is cut with a diamond knife at a cutting speed of 1.0 mm / sec and a cutting film thickness of 200 nm until it becomes a mirror surface. The sample with the exposed cross section is used for measurement based on the nanoindentation method in a state fixed with an AFM sample holding insert. As a cross-section cutting device, an ultrathin slicer EMUC7 manufactured by Leica is used. In addition, the cutting direction is set to a direction parallel to the layer interface.

[0166] <Determination of hardness and complex elastic modulus>

[0167] The hardness and complex elastic modulus of the anchor coating and the topcoat represent the hardness and complex elastic modulus calculated by nanoindentation. Nanoindentation is a measurement method that performs a quasi-static indentation test on the target measurement object to obtain the mechanical properties of the specimen. The measurement device uses Hysitron TI-Premier (trade name) manufactured by Bruker Japan Co., Ltd. The indenter uses a Berkovich-type diamond indenter manufactured by Bruker Japan Co., Ltd. The measurement based on nanoindentation first scans the specimen cross-section with the diamond indenter to obtain the shape image of the specimen and specifies the measurement position of the desired layer. Then, at room temperature (25 °C), it is indented to a depth of 80 nm at an indentation speed of 80 nm / second in displacement control mode, held at the maximum depth for 1 second, and then unloaded at a speed of 80 nm / second. Regarding the calculation method of hardness and complex elastic modulus, the fused silica that becomes the standard specimen is pre-tested to correct the relationship between the contact depth and the contact projected area of the indenter and the specimen. Then, the Oliver-Pharr method is used to analyze the unloading curve in the region of 60-95% of the maximum load during unloading, and the hardness and complex elastic modulus are calculated. The results are shown in Tables 1 to 4.

[0168] <Measurement of elongation at break point>

[0169] The measurement of the elongation at break point of the anchor coating and the topcoat was carried out as follows: The product obtained by coating and drying the coating liquid for forming the anchor coating and the topcoat on the support substrate was peeled off from the support substrate, punched into a dumbbell shape of Type 1A to make a test piece, and the measurement was carried out based on the method described in JIS K7161. As the device, an Autograph testing machine AGS-X (manufactured by Shimadzu Corporation) was used, the tensile test speed was set to 50 mm / minute, and the measurement was carried out in an environment of 20 °C and 65% humidity. The results are shown in Tables 1 to 4.

[0170] <Measurement of KIT value>

[0171] For the surface on the topcoat side of the laminate obtained in the examples and comparative examples, the oil resistance (KIT value) was measured by the TAPPI UM-557 method (kit method). In addition, while rolling a 1500 g roller at a speed of 300 mm / minute, a crease parallel to the MD direction was imparted to the laminate in such a way that the laminate became a valley fold when viewed from the paper substrate side (the topcoat became the outer surface), and similarly, the oil resistance (KIT value) of the crease part of the opened laminate was measured. The KIT value is expressed from grade 0 to grade 12, and the higher the number, the higher the oil resistance. The highest score of the oil resistance provided by the KIT test liquid that does not show penetration was used as the evaluation result. The KIT value is preferably 6 or more, and when it is less than 6, the oil resistance in food packaging may not be satisfied. The results are shown in Tables 1 to 4.

[0172] <Measurement of water vapor transmission rate>

[0173] The water vapor permeability (g / m2) of the laminates obtained in the examples and comparative examples in an atmosphere of 40°C and 90%RH was measured by the MOCON method according to JIS K7129-2. 2 / day). The water vapor permeability measuring device (manufactured by MOCON, trade name: PERMATRAN-W3 / 34G) was used for the measurement. Furthermore, the laminate was stored in a constant temperature and humidity chamber at 40°C and 90%RH for 1 week, and the same measurement was performed. The water vapor permeability at the initial stage and after storage at 40°C and 90%RH is shown in Tables 1 to 4.

[0174]

[0175]

[0176]

[0177]

[0178] As shown in Tables 1 to 4, the laminated bodies of the examples have good oil resistance (KIT value) not only at the initial stage but also after bending. In addition, as shown in Tables 1 to 4, it was confirmed that the water vapor permeability of the laminated bodies of the examples was 6 g / m after being stored at 40°C and 90% RH for 1 week. 2 / d or less, it is possible to maintain good water vapor barrier properties.

[0179] Description of Reference Numerals

[0180] 1 paper substrate; 2 anchor coating; 3 aluminum vapor deposition layer; 4 top coating; 10 laminate; 20 accordion bag; B1, B2 bending parts.

Claims

1. A laminate having a structure in which at least a paper substrate, an anchor coating layer, an aluminum vapor-deposited layer, and a top coating layer are sequentially laminated, in, The half-value width of the peak of the aluminum (111) crystal plane obtained by X-ray diffraction measurement of the aluminum vapor-deposited layer is 1.6° or more.

2. The laminate according to claim 1, in, The anchor coating layer includes a polyolefin or polyvinyl alcohol-based resin having a polar group.

3. The laminate according to claim 1, in, The topcoat layer comprises a polyolefin having polar groups.

4. The laminate according to claim 1, in, The hardness of the anchor coating layer measured by a nanoindentation method in a cross section in a thickness direction of the laminate is 0.3 GPa or less.

5. The laminate according to claim 1, in, The hardness of the top coating layer measured by a nanoindentation method in a cross section in a thickness direction of the laminate is 0.3 GPa or less.

6. The laminate according to claim 1, in, The aluminum vapor deposition layer has a thickness of 20 nm to 100 nm.

7. The laminate according to claim 1, in, The half-value width of the peak of the aluminum (111) crystal plane obtained by X-ray diffraction measurement of the aluminum vapor-deposited layer is 2.0° or more and 15.0° or less.

8. The laminate according to claim 7, in, The aluminum vapor-deposited layer is in contact with a resin layer containing an ionomer or a polyvinyl alcohol-based resin having a saponification degree of 95% or more. 9 . A packaging bag comprising the laminate according to claim 1 .

10. The packaging bag according to claim 9, comprising a bent portion.

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